This specification relates to information presentation.
The Internet provides access to a wide variety of resources, for example, webpages, images, audio files, and videos. Such access to these resources has likewise enabled opportunities for providing relevant additional content. One example of additional content is advertisements. For example, resources of particular interest to a user can be identified by a search engine in response to a user query. By comparing the user query to a list of keywords specified by a content sponsor, it is possible to provide relevant additional content to the user with search results.
Often, multiple content item providers compete to have their content items provided to users. For example, content sponsors may set bids for particular campaigns, and auctions may be conducted, where the content associated with the winning bidders is provided to users. The bids associated with content items may depend on various factors, and in some cases, one or more bids may be adjusted in order to provide the most relevant content items to users.